Main shaft system of multi-wire cutting machine and synchronous control method of main shaft system

Abstract

The invention discloses a main shaft system of a multi-wire cutting machine and a synchronous control method of the main shaft system, the multi-wire cutting machine comprises three main shafts and three driving rollers, the three main shafts are driven by three driving motors to rotate respectively, and the three driving rollers are installed on the three main shafts respectively; the driving motors are servo motors and can control the rotating speed of the main shaft and feed back the torque of the main shaft. The main shaft synchronous control method of the multi-wire cutting machine comprises the steps that torques fed back by the three main shafts are compared, when the torque fed back by one main shaft is too large, the rotating speeds of the other two main shafts are adjusted, the torques fed back by the three main shafts tend to be consistent, and the peripheral linear speeds of the three driving rollers tend to be consistent. In the invention, the cutting line is driven by multiple spindles, so that the load of each spindle can be equally divided, the linear speed of each spindle tends to be consistent, and the equipment can continuously and stably run.

Description

Technical Field

[0001] The present invention relates to the technical field of cutting equipment, and more specifically, to a spindle system of a multi-wire cutting machine, and also to a spindle synchronization control method of the multi-wire cutting machine. Background Art

[0002] Multi-wire cutting machines are usually driven by a single motor. For example, in a multi-wire cutting machine with seven rollers, the middle roller is usually used as the active roller. The static friction between the active roller and the cutting wire is used as the power to drive the cutting wire to run at high speed and realize the wire cutting action. When the cutting wire wrapped on the roller exceeds a certain length, it is easy to cause uneven force on the cutting wire if it is driven only by a single active roller. The response speed of the cutting wire is reduced during the forward and reverse switching process, and it cannot meet the process accuracy requirements of wire cutting. Therefore, in the case of longer cutting wires, multiple spindles are usually required for driving, which can shorten the distance between the cutting position of the cutting wire and the active roller, maintain the balanced force on the cutting wire, and ensure the response efficiency of the system.

[0003] If the multi-wire cutting machine system adopts multi-axis drive, the outer diameters of each active roller cannot be absolutely the same, and there will be processing precision errors. Even if the speed of each spindle is controlled to be consistent, there must be speed differences in the peripheral linear speeds of each active roller. Under the same speed, the larger the outer diameter of the active roller, the faster the linear speed will be, and it will drag the active roller with a slightly smaller outer diameter to speed up the speed to achieve the same linear speed of the three. The active roller with a large outer diameter and its corresponding drive motor need to bear a larger load and output a larger torque, while the active roller with a slightly smaller outer diameter and its corresponding drive motor output a smaller torque, which can easily cause some motors to overload and the equipment cannot work normally and stably.

[0004] Therefore, a new solution needs to be proposed to solve this problem. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and to provide a spindle system of a multi-wire cutting machine and a synchronous control method thereof. The cutting line adopts multi-spindle drive, which can evenly distribute the load of each spindle and keep the axis speed of each spindle consistent.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: A method for synchronously controlling the spindles of a multi-wire cutting machine, the multi-wire cutting machine comprising three spindles and three active rollers, the three spindles being driven to rotate by three driving motors respectively, and the three active rollers being respectively mounted on the three spindles; the driving motors are all servo motors, which can respectively control the rotation speed of the spindles and can feed back the torque of the spindles; The spindle synchronization control method of the multi-wire cutting machine is as follows: comparing the torques fed back by the three spindles, when the torque fed back by one of the spindles is too large, adjusting the rotation speeds of the other two spindles, the torques fed back by the three spindles tend to be consistent, and the peripheral line speeds of the three active rollers tend to be consistent.

[0007] The present invention is further configured that the spindle synchronization control method of the multi-wire cutting machine comprises the following steps: S1: Create a virtual axis with a standard outer diameter, and control the rotation speed Vvirtual of the virtual axis according to the linear speed requirements of the cutting process; S2: Establish virtual gear ratios between the virtual axis and the three main axes, namely G1, G2, and G3. The speeds of the three main axes and the virtual axis are coupled and adjusted. The initial values ​​of G1, G2, and G3 are 1. S3: The speeds of the three spindles are V1, V2, and V3 respectively. The speeds of the three spindles are controlled with the speed of the virtual axis as the target speed, V1 = Vvirtual·G2, V2 = Vvirtual·G2, V3 = Vvirtual·G3; S4: Read the torque feedback from the three spindles in real time. The torque values ​​of the three spindles are T1, T2, and T3 respectively. Take the maximum value Tmax of the torque feedback from the three spindles, Tmax=max{T1, T2, T3}, and calculate and compare the difference ratio between T1, T2, T3 and Tmax. S5: If the difference ratio does not exceed the preset value, the initial coupling between the virtual axis and the three spindles is successful, and the spindles can run in high-speed mode; if the difference ratio exceeds the preset value, the initial coupling between the virtual axis and the three spindles is unsuccessful, and the spindles run in low-speed mode for adjustment; S6: The spindle runs in low-speed mode to initially adjust the rotation speed of the three spindles and the initial virtual gear ratios G1, G2, and G3; the initial virtual gear ratios G1, G2, and G3 are adjusted according to the torque feedback from the three spindles. The spindle with the maximum torque is not adjusted, and the virtual gear ratios of the other two spindles are adjusted until the difference ratio between T1, T2, T3 and Tmax does not exceed the preset value, and the spindle can run in high-speed mode.

[0008] The present invention is further configured such that, in step S6, adjustment coefficients K1 initial, K2 initial, and K3 initial are set to adjust the initial virtual gear ratios of the three main shafts respectively, to obtain virtual gear ratios G1′, G2′, and G3′, G1′=K1 initial·G1, G2′=K2 initial·G2, and G3′=K3 initial·G3.

[0009] The present invention is further configured to further include step S7, S7: the spindle runs in high-speed mode, the torque fed back by the three spindles is read in real time, and the virtual gear ratio is adjusted according to the torque fed back by the three spindles; the torque values ​​fed back by the three spindles are T1, T2, and T3 respectively; the maximum value Tmax of the torque fed back by the three spindles is taken, Tmax=max{T1, T2, T3}, and the difference ratio between T1, T2, T3 and Tmax is calculated and compared; If the difference ratio does not exceed the preset value, the virtual gear ratios of the three spindles will not be adjusted; If the difference ratio exceeds the preset value, adjust the virtual teeth of the three main shafts until the difference ratio of T1, T2, T3 and Tmax does not exceed the preset value.

[0010] The present invention is further configured such that, in step S7, adjustment coefficients K1 synchronization, K2 synchronization, and K3 synchronization are set to adjust the virtual gear ratio to obtain virtual gear ratios G1′′, G2′′, and G3′′, G1′′=K1 synchronization·G1, G2′′=K2 synchronization·G2, G2′′=K3 synchronization·G2, and the spindle with maximum torque is not adjusted.

[0011] The present invention is further configured such that, in step S7, when the virtual gear ratios of the three spindles are adjusted, the spindle with the maximum torque is not adjusted, and the virtual gear ratios of the other two spindles are adjusted, the rotational speeds of the three spindles are coupled, and the peripheral linear speeds of the three active rollers tend to be consistent.

[0012] The present invention is further configured such that the three spindles are arranged along the winding direction of the cutting line, and are divided into a left spindle, a right spindle and a middle spindle, wherein the middle spindle is located in the middle of the left spindle and the right spindle; In step S7, when the virtual gear ratios of the three spindles are adjusted, the middle spindle is in speed operation mode, the rotation speed of the middle spindle V3 = Vvirtual G3, and the torque value fed back by the middle spindle is T3; the left spindle and the right spindle are operated in torque mode, the torque of the left spindle and the right spindle are adjusted, and the torque value fed back by the left spindle and the right spindle is maintained consistent with the torque value fed back by the middle spindle, T1 = T3, T2 = T3; the torques fed back by the three spindles tend to be consistent.

[0013] The present invention also provides a spindle system of a multi-wire cutting machine, comprising three spindles and three active rollers, the three spindles are driven to rotate by three driving motors respectively, and the three active rollers are respectively installed on the three spindles; the driving motors are all servo motors, which can control the rotation speed of the spindles respectively and can feedback the torque of the spindles; the three spindles of the spindle system are controlled by the spindle synchronization control method of the multi-wire cutting machine as mentioned above.

[0014] The present invention is further configured to include four driven rollers, and the four driven rollers and three active rollers are all installed on the frame for the cutting line to pass around; the four driven rollers can be driven to rotate by the friction of the cutting line.

[0015] The present invention is further configured such that, along the winding direction of the cutting line, at least one driven roller is spaced between the two active rollers.

[0016] In summary, the present invention has the following beneficial effects: During the operation of the equipment, by comparing the torque feedback from the three spindles, when the torque feedback from one of the spindles is too large, the spindle speed can be adjusted, the torque feedback from the three spindles tends to be consistent, and the peripheral speeds of the three active rollers tend to be consistent. The three spindles can evenly divide the total load and can be stably applied to the operation of the equipment. The torque feedback from the spindles is obtained, so that the three spindles can form a dynamic balance.

[0017] The spindle system can be adjusted in both the initial stage and high-speed stage of operation. In the initial stage of the equipment, it can run at a lower speed and make initial adjustments to the rotation speeds of the three spindles. In the low-speed stage, the differences in the linear speeds of the three spindles have little impact, and through adjustment, the linear speeds of the three spindles can be made consistent, allowing the spindles to enter high-speed operation normally.

[0018] There are differences in the precision of the outer diameters of the three spindles, and there are also differences in the outer diameters of each axial position of a single spindle. As the cutting line winds, the position where the cutting line first bypasses the spindle will also change, which will cause the difference in the axial outer diameter of the spindle to affect the linear speed of the cutting line. The spindle system can also be fine-tuned during high-speed operation to maintain the dynamic balance of the three spindles, roughly evenly distribute the load of the three axes, and ensure that the linear speeds of the three active rollers tend to be consistent, ensuring that the three spindles can be dynamically balanced during high-speed operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic structural diagram of a multi-wire cutting machine in this embodiment; Figure 2 This is a schematic structural diagram of a spindle system of a multi-wire cutting machine in this embodiment; Figure 3 is a flow chart of the spindle synchronization control method in this embodiment; Figure 4 is a flow chart of the first high-speed mode in this embodiment; Figure 5 This is a flow chart of the second high-speed mode in this embodiment.

[0020] Figure numerals: 1. active roller; 11. left active roller; 12. right active roller; 13. middle active roller; 2. driving motor; 21. left driving motor; 22. right driving motor; 23. middle driving motor; 3. spindle; 31. left spindle; 32. right spindle; 33. middle spindle; 4. cutting line; 5. driven roller. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] This embodiment discloses a spindle system of a multi-wire cutting machine. Figure 1 , Figure 2 As shown, it includes several rollers installed on the frame, each roller can allow the cutting line 4 to pass around, specifically, there are 7 rollers in total, which are divided into active rollers 1 and driven rollers 5, the number of active rollers 1 is 3, and the number of driven rollers 5 is 4. The 7 rollers are roughly distributed in an inverted trapezoidal structure, which can stably guide the cutting line 4, form a static friction motion state, and avoid the cutting line 4 from slipping with the roller surface.

[0023] The spindle system also includes three drive motors 2, three spindles 3 and three active rollers 1. The three active rollers 1 are parts of the rollers and are respectively installed on the three spindles 3. The three spindles 3 are motor shafts of the three drive motors 2, and the spindles 3 are driven by the drive motors 2 to rotate.

[0024] The three driving motors 2 are all servo motors, which can control the rotation speed of the main shaft 3 respectively, control the three active rollers 1 to rotate independently, and can feedback the torque of the main shaft 3, and can also adjust the rotation speed of the main shaft 3 with the feedback torque.

[0025] Along the winding direction of the cutting wire 4, there is at least one driven roller 5 between two active rollers 1, and the active rollers 1 are relatively evenly distributed at different positions of the winding, so that the friction load of the active rollers 1 on the cutting wire 4 can be evenly distributed.

[0026] The three spindles 3 are arranged along the winding direction of the cutting line 4, and are divided into a left spindle 31, a right spindle 32 and a middle spindle 33, wherein the middle spindle 33 is located in the middle of the left spindle 31 and the right spindle 32. The three drive motors 2 correspond to the positions of the three spindles 3 and are installed on the frame.

[0027] Specifically, the three active rollers 1 are respectively a left active roller 11, a right active roller 12 and a middle active roller 13; the three drive motors 2 are respectively a left drive motor 21, a right drive motor 22 and a middle drive motor 23, the left drive motor 21 includes a left main shaft 31, the left active roller 11 is installed on the left main shaft 31, the right drive motor 22 includes a right main shaft 32, the right active roller 12 is installed on the right main shaft 32, the middle drive motor 23 includes a middle main shaft 33, and the middle active roller 13 is installed on the middle main shaft 33.

[0028] In the horizontal direction, the left active roller 11 and the right active roller 12 are respectively located at the two sides of each roller, and the middle active roller 13 is located in the middle of each roller, forming a left, middle and right distribution state. The three active rollers 1 distributed on the left, middle and right can shorten the distance from the working position of the cutting line 4 to the active roller 1, and can also improve the response efficiency of the equipment when switching between forward and reverse directions.

[0029] By synchronously controlling the rotation speed of the main shaft 3 of the three driving motors 2, the total load of the cutting line 4 can be evenly divided, so that the linear speed of the outer periphery of each active roller 1 can be consistent, ensuring that the cutting line 4 is not broken, maintaining the same tension force on the cutting line 4 at different positions, and ensuring cutting accuracy.

[0030] Since the outer diameters of the three active rollers 1 cannot be absolutely the same, the cutting wires 4 wound around the three active rollers 1 must have a linear speed difference at the same motor speed. Under the same speed, the larger the outer diameter of the active roller 1, the faster the linear speed, which will drag the active roller 1 with a slightly smaller outer diameter to speed up the speed so that the three linear speeds are the same. At this time, the active roller 1 with a large outer diameter and its corresponding drive motor 2 need to bear a larger load and output a larger torque, while the active roller 1 with a slightly smaller outer diameter and its corresponding drive motor 2 output a smaller torque, forming a vicious circle, causing a motor to overload and the equipment to be unable to work normally and stably.

[0031] During the operation of the equipment, by comparing the torques fed back by the three spindles 3, when the torque fed back by one of the spindles 3 is too large, the rotation speeds of the other two spindles 3 are adjusted, and the torques fed back by the three spindles 3 tend to be consistent, and the peripheral line speeds of the three active rollers 1 tend to be consistent. The three spindles 3 can evenly divide the total load and can be stably applied to the operation of the equipment, so that the three spindles 3 can form a dynamic balance.

[0032] The present embodiment also discloses a spindle synchronization control method for a multi-wire cutting machine, which can control the spindle system of the multi-wire cutting machine in the above embodiment, dynamically adjust the rotation speed of the three spindles 3, keep the linear speed of the periphery of the three active rollers 1 tending to be consistent, balance the load of the three drive motors 2, and keep the equipment running stably for a long time.

[0033] Reference Figure 3 As shown, the synchronous control method includes the following steps: S1: Establish a virtual axis with a standard outer diameter; use the peripheral linear speed of the virtual axis as the cutting linear speed, and control the rotation speed Vvirtual of the virtual axis according to the linear speed requirements of the cutting process; specifically, the rotation speed of the virtual axis is the theoretical rotation speed of the active roller 1, the outer diameter of the virtual axis is also the size required for processing the active roller 1, and there is no precision error in the virtual axis.

[0034] S2: Establish virtual gear ratios between the virtual axis and the three spindles 3, which are G1, G2, and G3 respectively. The speeds of the three spindles 3 and the virtual axis are coupled and adjusted; the speeds of the three spindles 3 are controlled by the virtual axis, and the initial values ​​of G1, G2, and G3 are 1. The initial value of the virtual gear ratio is 1. After running, it is adjusted according to the feedback value. Moreover, since the running speed of the spindle 3 is low during the initial adjustment, the precision error between the spindles 3 is reflected in the difference in linear speed, which does not affect the initial operation of the equipment.

[0035] S3: The rotation speeds of the three spindles 3 are V1, V2, and V3 respectively. The rotation speeds of the three spindles 3 are controlled with the rotation speed of the virtual axis as the target rotation speed, V1 = Vvirtual·G2, V2 = Vvirtual·G2, and V3 = Vvirtual·G3.

[0036] S4: Read the torque feedback from the three spindles 3 in real time. The torque values ​​feedback from the three spindles 3 are T1, T2, and T3 respectively. Take the maximum value Tmax of the torque feedback from the three spindles 3, Tmax=max{T1, T2, T3}, and calculate and compare the difference ratio between T1, T2, T3 and Tmax.

[0037] S5: If the difference ratio does not exceed the preset value, it means that the load difference of the three spindles 3 is small and the load is basically divided equally, then the initial coupling between the virtual axis and the three spindles 3 is successful, and the spindle system can run in high-speed mode; if the difference ratio exceeds the preset value, it means that the load difference of the three spindles 3 is large, and the load carried by one of the spindles 3 is too large, then the initial coupling between the virtual axis and the three spindles 3 is unsuccessful, and the spindle system runs in low-speed mode. In general, the preset value of the difference ratio is set to 5%, and it can also be set specifically according to the accuracy requirements.

[0038] Specifically, the low-speed operation mode of the spindle system has a linear speed of less than 10m / min, which is usually used for equipment preheating and initial adjustment before startup; while the high-speed mode has a faster linear speed, which is usually used for normal cutting work of the equipment. The operating speed of the high-speed mode can be set according to actual cutting requirements.

[0039] S6: The spindle system runs in low-speed mode to initially adjust the rotational speeds of the three spindles 3 and the initial virtual gear ratios G1, G2, and G3; the initial virtual gear ratios G1, G2, and G3 are adjusted according to the torques fed back from the three spindles 3, and the spindle 3 with the maximum torque is not adjusted. The virtual gear ratios of the other two spindles 3 are increased until the difference ratios of T1, T2, and T3 to Tmax do not exceed the preset value, and the spindle system can run in high-speed mode.

[0040] In the process of adjusting the initial virtual gear ratios G1, G2, and G3, the adjustment coefficient K initial is set. The adjustment coefficients of the three spindles 3 are K1 initial, K2 initial, and K3 initial, respectively, which are used to adjust the initial virtual gear ratios of the three spindles 3 to obtain virtual gear ratios G1′, G2′, and G3′, G1′=K1 initial·G1, G2′=K2 initial·G2, and G3′=K3 initial·G3. The adjustment coefficient K initial is a PID parameter related to the (Tmax-T) / Tmax difference ratio, which can form dynamic adjustment until the torque difference ratio of the three spindles 3 reaches the requirement and the loads on the three spindles 3 are balanced.

[0041] The adjustment coefficient K initial corresponding to each main axis 3 can change the state during the adjustment process. K initial is used for fast large-proportion adjustment synchronization. After the coupling synchronization is completed, the K initial value is fixed to achieve initial coupling. K initial is related to Kp, △k, and e(t). Specifically, K initial = Kp·△k·e(t).

[0042] Among them, Kp= f(ARRAY_Ti[0..19]), the value of Kp is related to the frequency of change of the feedback torque difference ratio of spindle 3. The three feedback torque difference ratio storage stacks ARRAY_Ti[0..19] of spindle 3 are set respectively to continuously judge the data value. The more times the difference ratio exceeds the preset value, the greater the Kp value will be. Conversely, the fewer times the difference ratio exceeds the preset value, the smaller the Kp value will be.

[0043] Among them, △k=f(ARRAY_Vvirtual[0..19]), the value of △k is related to the speed of the virtual axis. During the operation of the equipment, the speed of the wire cutting may need to be adjusted, so the speed of the virtual axis will also be adjusted as needed. Set the virtual axis speed segmentation judgment threshold stack ARRAY_Vvirtual[0..19], △k is positively correlated with the speed of the virtual axis. The faster the virtual axis, the faster the △k adjustment speed.

[0044] Among them, e(t) is the compensation value of the torque deviation, e(t) = torque deviation value · compensation proportional coefficient, which is related to the torque deviation value and the rotation compensation ratio (generally, the torque deviation value takes an absolute value, and can be controlled in the forward and reverse directions according to the positive and negative difference of the torque). The torque deviation value is the difference between the feedback torque Ti and Tmax of the corresponding spindle. The compensation proportional coefficient can be set specifically according to the adjustment progress requirements, and is generally positively correlated with the difference ratio between the feedback torque Ti and Tmax, that is, the larger the difference ratio, the larger the rotation compensation proportional coefficient will be. By setting the compensation value of the torque deviation, when the torque difference is large, by increasing the adjustment compensation value, the rotation linear speed and torque of each spindle can be adjusted to a close state more quickly.

[0045] S7: The spindle system runs in high-speed mode. When running in high-speed mode, the rotation speeds of the three spindles 3 can still be monitored and adjusted, and the virtual gear ratios G1, G2, and G3 are fine-tuned to achieve dynamic balance between the three spindles 3; the spindles 3 run in high-speed mode, and the torques fed back by the three spindles 3 are read in real time, and the virtual gear ratios are adjusted according to the torques fed back by the three spindles 3; the torque values ​​fed back by the three spindles 3 are T1, T2, and T3 respectively; the maximum value Tmax of the torques fed back by the three spindles 3 is taken, Tmax=max{T1, T2, T3}, and the difference ratios of T1, T2, T3 and Tmax are calculated and compared; If the difference ratio does not exceed the preset value, the virtual gear ratios of the three main shafts 3 are not adjusted, which means that the three main shafts 3 are in a good balance state, have been coupled with each other, and continue to operate in a balanced state; If the difference ratio exceeds the preset value, the virtual teeth of the three main shafts 3 are adjusted until the difference ratio between T1, T2, T3 and Tmax does not exceed the preset value.

[0046] Reference Figure 4 , Figure 5 As shown, the adjustment of the high-speed mode is divided into two modes, namely the first high-speed mode and the second high-speed mode.

[0047] Reference Figure 4 As shown, in the first high-speed mode, the rotation speed of the three spindles 3 is adjusted according to the rotation speed of the virtual axis, the rotation speed of the virtual axis is first obtained (which can be obtained by the cutting speed required by the process), and then the feedback torque of the three spindles is obtained, and the rotation speed of the three spindles 3 is adjusted according to the feedback torque; the synchronization adjustment coefficient K is set, and then the synchronization virtual gear ratio G′′ is obtained according to K synchronization, and the rotation speed of the three spindles 3 is coupled with the rotation speed of the virtual axis according to the virtual gear ratio, that is, the linear speed of the three active rollers 1 is consistent with the linear speed of the spindle 3. After the linear speed of the three spindles 3 is coupled with the linear speed of the virtual axis, it is dynamically adjusted according to the feedback torque of the three spindles 3.

[0048] Specifically, the adjustment coefficients K1 synchronization, K2 synchronization, and K3 synchronization are set to adjust the virtual gear ratios to obtain virtual gear ratios G1′′, G2′′, and G3′′, where G1′′=K1 synchronization·G1, G2′′=K2 synchronization·G2, and G2′′=K3 synchronization·G2; wherein, the spindle 3 with the maximum torque is not adjusted, and the rotational speeds of the other two spindles 3 are adjusted, so that the feedback torque of the spindle 3 with the maximum torque will be reduced, thereby achieving mutual coupling of the rotational speeds of the three spindles 3, the peripheral linear speeds of the three active rollers 1 also tend to be consistent, and the feedback torque also tends to be consistent, thereby achieving dynamic balance of the three spindles 3.

[0049] The adjustment coefficient K synchronization corresponding to each main shaft 3 can change the state during the adjustment process. K synchronization is used to stably fine-tune the rotation state of each main shaft 3 to achieve stable coupling. K synchronization is related to K initial, △k, and e(t). Specifically, K synchronization = K initial·△k′·e(t).

[0050] Ksync is the value corresponding to the initial synchronization adjustment. Ksync is related to Kinitial and can be supplemented and adjusted based on the initial adjustment.

[0051] Among them, △k′=f(ARRAY_V dummy′[0..19]). Since the speed in high-speed mode is different from the speed in initial adjustment, the △k′ value is also different from the above △k. △k′ is related to the virtual axis speed in high-speed mode. Set the virtual axis speed segmentation judgment threshold stack ARRAY_V dummy′[0..19]. The faster the virtual axis, the faster the △k′ adjustment speed.

[0052] Among them, e(t) is the compensation value of the torque deviation, which is consistent with the above, e(t) = torque deviation value · compensation proportional coefficient, which is related to the torque deviation value and the rotation compensation ratio (generally, the torque deviation value takes an absolute value, and can be controlled for forward and reverse rotation according to the positive and negative difference of the torque). The torque deviation value is the difference between the feedback torque Ti and Tmax of the corresponding spindle. The compensation proportional coefficient can be specifically set according to the requirements of the adjustment progress, and is generally positively correlated with the difference ratio of the feedback torque Ti and Tmax, that is, the larger the difference ratio, the larger the rotation compensation proportional coefficient will be.

[0053] Reference Figure 5As shown, in the second high-speed mode, adjustments are made according to the torque conditions of the three spindles 3. First, according to the rotation speed of the virtual axis and the feedback torque of the three spindles 3, the rotation speed of the middle spindle 33 is coupled with the rotation speed of the virtual axis. The middle spindle 33 is in the rotation speed operation mode to maintain the rotation speed of the middle axis. The rotation speed V3 of the middle spindle 33 = V virtual G3, and the torque value fed back by the middle spindle 33 is T3. The left spindle 31 and the right spindle 32 are operated in the torque mode, and the torque of the left spindle 31 and the right spindle 32 are coupled. The torque of the left spindle 31 and the right spindle 32 is adjusted based on the torque value fed back by the middle spindle 33, and the torque values ​​fed back by the left spindle 31 and the right spindle 32 are maintained consistent with the torque value fed back by the middle spindle 33, T1 = T3, T2 = T3, and the torques of the three spindles 3 are kept balanced.

[0054] After adjustment, the torque value T3 fed back by the middle spindle 33 will change, and then the other two spindles 3 will be adjusted according to the changed feedback torque value. The torques fed back by the three spindles 3 tend to be consistent, and the peripheral linear speeds of the three active rollers 1 also tend to be consistent. In addition, the linear speed of the cutting line 4 will remain roughly consistent during the adjustment process.

[0055] During the winding process of the cutting wire 4, since the number of turns of the cutting wire 4 is small and the rollers are not fully wound, the static friction between the cutting wire 4 and the rollers is not large enough, and the first high-speed mode is usually used. After the winding is completed, when the cutting wire 4 is cutting, the second high-speed mode is used. The two operating modes can be applied to different operating states of the equipment.

[0056] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A spindle synchronization control method for a multi-wire cutting machine, characterized in that: The multi-wire cutting machine comprises three main shafts (3) and three active rollers (1); the three main shafts (3) are respectively driven to rotate by three driving motors (2); the three active rollers (1) are respectively mounted on the three main shafts (3); the driving motors (2) are all servo motors, which can respectively control the rotation speed of the main shafts (3) and can feed back the torque of the main shafts (3); The spindle synchronization control method of the multi-wire cutting machine comprises: comparing the torques fed back by the three spindles (3); when the torque fed back by one of the spindles (3) is too large, adjusting the rotation speeds of the other two spindles (3); the torques fed back by the three spindles (3) tend to be consistent; and the peripheral line speeds of the three active rollers (1) tend to be consistent.

2. The spindle synchronization control method of the multi-wire cutting machine according to claim 1, characterized in that: The steps include: S1: Create a virtual axis with a standard outer diameter, and control the rotation speed Vvirtual of the virtual axis according to the linear speed requirements of the cutting process; S2: establishing virtual gear ratios between the virtual axis and the three main axes (3), which are G1, G2, and G3 respectively. The speeds of the three main axes (3) and the virtual axis are coupled and adjusted. The initial values ​​of G1, G2, and G3 are 1. S3: The rotation speeds of the three main axes (3) are V1, V2, and V3 respectively. The rotation speeds of the three main axes (3) are controlled respectively with the rotation speed of the virtual axis as the target rotation speed, V1 = Vvirtual·G2, V2 = Vvirtual·G2, V3 = Vvirtual·G3; S4: read the torque feedback from the three main axes (3) in real time, the torque values ​​feedback from the three main axes (3) are T1, T2, and T3 respectively; take the maximum value Tmax of the torque feedback from the three main axes (3), Tmax=max{T1, T2, T3}, and calculate and compare the difference ratio between T1, T2, T3 and Tmax; S5: If the difference ratio does not exceed the preset value, the initial coupling between the virtual axis and the three spindles (3) is successful, and the spindles (3) can run in high-speed mode; if the difference ratio exceeds the preset value, the initial coupling between the virtual axis and the three spindles (3) is unsuccessful, and the spindles (3) are adjusted in low-speed mode; S6: The spindle (3) runs in low-speed mode to initially adjust the rotation speeds of the three spindles (3) and the initial virtual gear ratios G1, G2, and G3; the initial virtual gear ratios G1, G2, and G3 are adjusted according to the torques fed back from the three spindles (3), the spindle (3) with the maximum torque is not adjusted, and the virtual gear ratios of the other two spindles (3) are adjusted until the difference ratios of T1, T2, and T3 to Tmax do not exceed the preset value, and the spindle (3) can run in high-speed mode.

3. The spindle synchronization control method of the multi-wire cutting machine according to claim 2, characterized in that: In step S6, adjustment coefficients K1 initial, K2 initial, and K3 initial are set to adjust the initial virtual gear ratios of the three main shafts (3) respectively, to obtain virtual gear ratios G1′, G2′, and G3′, G1′=K1 initial·G1, G2′=K2 initial·G2, and G3′=K3 initial·G3.

4. The spindle synchronization control method of a multi-wire cutting machine according to claim 2, characterized in that: The method further comprises step S7, wherein: the spindle (3) runs in high-speed mode, and the torque fed back by the three spindles (3) is read in real time, and the virtual gear ratio is adjusted according to the torque fed back by the three spindles (3); the torque values ​​fed back by the three spindles (3) are T1, T2, and T3 respectively; the maximum value Tmax of the torque fed back by the three spindles (3) is taken, Tmax=max{T1, T2, T3}, and the difference ratio between T1, T2, T3 and Tmax is calculated and compared; If the difference ratio does not exceed the preset value, the virtual gear ratios of the three main axes (3) are not adjusted; If the difference ratio exceeds the preset value, the virtual teeth of the three main shafts (3) are adjusted until the difference ratio between T1, T2, T3 and Tmax does not exceed the preset value.

5. The spindle synchronization control method of a multi-wire cutting machine according to claim 4, characterized in that: In step S7, the adjustment coefficients K1 synchronization, K2 synchronization, and K3 synchronization are set to adjust the virtual gear ratios to obtain virtual gear ratios G1′′, G2′′, and G3′′, where G1′′=K1 synchronization·G1, G2′′=K2 synchronization·G2, and G2′′=K3 synchronization·G2. The spindle (3) with the maximum torque is not adjusted.

6. The spindle synchronization control method of a multi-wire cutting machine according to claim 4, characterized in that: In step S7, when the virtual gear ratios of the three main shafts (3) are adjusted, the main shaft (3) with the maximum torque is not adjusted, and the virtual gear ratios of the other two main shafts (3) are adjusted, the rotational speeds of the three main shafts (3) are coupled, and the peripheral linear speeds of the three active rollers (1) tend to be consistent.

7. The spindle synchronization control method of a multi-wire cutting machine according to claim 4, characterized in that: The three main shafts (3) are arranged along the winding direction of the cutting line (4), and are divided into a left main shaft (31), a right main shaft (32) and a middle main shaft (33), wherein the middle main shaft (33) is located in the middle position between the left main shaft (31) and the right main shaft (32); In step S7, when the virtual gear ratios of the three spindles (3) are adjusted, the middle spindle (33) is in speed operation mode, the rotation speed V3 of the middle spindle (33) is V virtual G3, and the torque value fed back by the middle spindle (33) is T3; the left spindle (31) and the right spindle (32) are operated in torque mode, the torques of the left spindle (31) and the right spindle (32) are adjusted, and the torque values ​​fed back by the left spindle (31) and the right spindle (32) are maintained consistent with the torque values ​​fed back by the middle spindle (33), T1=T3, T2=T3; the torques fed back by the three spindles (3) tend to be consistent.

8. A spindle system of a multi-wire cutting machine, characterized in that: The invention comprises three main shafts (3) and three active rollers (1), wherein the three main shafts (3) are driven to rotate respectively by three driving motors (2), and the three active rollers (1) are respectively installed on the three main shafts (3); the driving motors (2) are all servo motors, which can respectively control the rotation speed of the main shaft (3) and can feed back the torque of the main shaft (3); the main shaft synchronization control method of the multi-wire cutting machine as described in any one of claims 1 to 7 is adopted to control the three main shafts (3) of the main shaft system.

9. The spindle system of the multi-wire cutting machine according to claim 8, characterized in that: It also includes four driven rollers (5), which are all installed on the frame and three active rollers (1) for the cutting wire (4) to pass around; the four driven rollers (5) can be driven to rotate by the friction of the cutting wire (4).

10. The spindle system of the multi-wire cutting machine according to claim 8, characterized in that: Along the winding direction of the cutting line (4), at least one driven roller (5) is spaced between the two active rollers (1).

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